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Sep 22, 2013
09/13

by
Sang-Jin Sin

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We study the localized tachyon condensation in their mirror Landau-Ginzburg picture. We completely determine the decay mode of an unstable orbifold $C^r/Z_n$, $r=1,2,3$ under the condensation of a tachyon with definite R-charge and mass by extending the Vafa's work hep-th/0111105. Here, we give a simple method that works uniformly for all $C^r/Z_n$. For $C^2/Z_n$, where method of toric geometry works, we give a proof of equivalence of our method with toric one. For $C^r/Z_n$ cases, the...

Source: http://arxiv.org/abs/hep-th/0308028v1

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Sep 22, 2013
09/13

by
Sang-Jin Sin

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We study the localized tachyon condensation (LTC) of non-supersymmetric orbifold backgrounds in their mirror Landau-Ginzburg picture. Using he existence of four copies of (2,2) worldsheet supersymmetry, we show at the CFT level, that the minimal tachyon mass in twisted sectors shows somewhat analogous properties of c- or g-function. Namely, $m := |\alpha' M^2_{min}| $ satisfies $m(M) \geq m(D_1\oplus D_2)={\rm max} \{m(D_1),m(D_2)\}$. $c$- $g$- $m$- functions share the common property $...

Source: http://arxiv.org/abs/hep-th/0308015v1

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Sep 21, 2013
09/13

by
Sang-Jin Sin

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We consider the ultra light pseudo Nambu-Goldstone boson appearing in the late time cosmological phase transition theories as a dark matter candidate. Since it is almost massless, its nature is more wave like than particle like. Hence we apply quantum mechanics to study how they form the galactic halos. Three predictions are made; (1)the mass profile $\rho\sim r^{-1.6}$, (2)there are ripple-like fine structures in rotation curve, (3) the rotation velocity times ripple's wave length is largely...

Source: http://arxiv.org/abs/hep-ph/9205208v1

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Sep 18, 2013
09/13

by
Sang-Jin Sin

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We discuss the localized tachyon condensation in the non-supersymmetric orbifold theories by taking the cosmological constant as the measure of degrees of freedom (d.o.f). We first show asymptotic density of state is not a proper quantity to count the 'localized' d.o.f. We then show that localized d.o.f lead us a c-function given by the lightest tachyon mass, which turns out to be the same as the tachyon potential recently suggested by Dabholkar and Vafa. We also argue that delocalized d.o.f...

Source: http://arxiv.org/abs/hep-th/0202097v3

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Sep 18, 2013
09/13

by
Sang-Jin Sin

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We consider the gravity back reaction on the metric due to the baryon density in effective ads/qcd model by reconsidering the role of the charged AdS black hole. Previously it has been known that the U(1) charge is dual to the R-charge. Here we point out that if we consider the case where $AdS_5$ is completely filled with $N_f$ flavor branes, the gravity back reaction produces charged AdS black hole where the effect of charge on the metric is proportional to $N_f/N_c$. As a consequence, phase...

Source: http://arxiv.org/abs/0707.2719v3

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Sep 19, 2013
09/13

by
Sang-Jin Sin

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The paper is withdrawn by the author. Parts of the contents are expanded into separate papers; hep-th/0308015 LOCALIZED TACHYON MASS AND A G-THEOREM ANALOGUE, hep-th/0308028 COMMENTS ON THE FATE OF UNSTABLE ORBIFOLDS, hep-th/0308029 CHIRAL RINGS AND GSO PROJECTION IN ORBIFOLDS.

Source: http://arxiv.org/abs/hep-th/0303138v2

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Sep 19, 2013
09/13

by
Sang-Jin Sin

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We study the holomorphic properties of the MQCD by comparing the super-potentials in MQCD and the gauge theory. First we show that the super-potential defined as an integral of three form is NOT appropriate for generic situation with quarks. We report a resolution of the problem which works for the brane configurations of 90 degree rotation, including the true SQCD. The new definition does not need auxiliary surface and can be reduced to a contour integral for some cases. We find relation...

Source: http://arxiv.org/abs/hep-th/9801032v2

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Sep 22, 2013
09/13

by
Soonkeon Nam; Sang-Jin Sin

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We consider condensation of localized closed string tachyons by examining the recent proposal of Harvey, Kutasov, Martinec, and Moore. We first observe that the $g_{\rm cl}$ defined by HKMM does not reflect the space-time supersymmetry when the model has the SUSY. Especially for ${\bf C}^2/{\bf Z}_N$ models, $g_{\rm cl}$ defined by them is highly peaked along the supersymmetric points in the space of orbifolds, which is unsatisfactory property of the "potential" of the RG-flow. We...

Source: http://arxiv.org/abs/hep-th/0201132v2

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Jun 30, 2018
06/18

by
Shigenori Seki; Sang-Jin Sin

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We study the causal structure of the minimal surface of the four-gluon scattering, and find a world-sheet wormhole parametrized by Mandelstam variables, thereby demonstrate the EPR = ER relation for gluon scattering. We also propose that scattering amplitude is the change of the entanglement entropy by generalizing the holographic entanglement entropy of Ryu-Takayanagi to the case where two regions are divided in space-time.

Topic: High Energy Physics - Theory

Source: http://arxiv.org/abs/1404.0794

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Sep 22, 2013
09/13

by
Eunseok Oh; Sang-Jin Sin

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In the flat space, non-spherical shells collapse to give globular cluster after many oscillations. We show that in anti de sitter space, they form black holes in one dynamical time. We propose that this is the mechanism of early thermalization in strong quark-gluon plasma in gravity dual. This is traced back to the a remarkable property of AdS : the period in radial motion is amplitude independent in spite of the NON-linearity of the equation of motion. We investigate the interaction effect...

Source: http://arxiv.org/abs/1302.1277v3

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Sep 22, 2013
09/13

by
Matthias Klein; Sang-Jin Sin

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We derive the effective superpotential for an N=1 SU(N_c) gauge theory with one massless adjoint field and N_f massless fundamental flavors and cubic tree-level superpotential for the adjoint field. This is a generalization of the Affleck-Dine-Seiberg superpotential to gauge theories with one massless adjoint matter field. Using Kutasov's generalization of Seiberg duality, we then find the effective superpotential for a related theory with massive fundamental flavors.

Source: http://arxiv.org/abs/hep-th/0309044v1

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Jul 20, 2013
07/13

by
Shigenori Seki; Sang-Jin Sin

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We consider the model of holographic QCD with asymptotic freedom and gluon condensation in its vacuum. It consists of the color D4-branes and D0-branes as a background and the flavor D8-branes as a probe. By taking a specific field theory limit, the effective coupling decreases to vanish in UV region. We then introduce the uniformly distributed baryons in terms of the baryon vertices and study the density dependence of chiral condensate, which is evaluated using the worldsheet instanton method....

Source: http://arxiv.org/abs/1304.7097v1

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Sep 22, 2013
09/13

by
Sunggeun Lee; Sang-Jin Sin

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The GSO projection in the twisted sector of orbifold background is sometimes subtle and incompatible descriptions are found in literatures. Here, from the equivalence of partition functions in NSR and GS formalisms, we give a simple rule of GSO projection for the chiral rings of string theory in $\C^r/\Z_n$, $r=1,2,3$. Necessary constructions of chiral rings are given by explicit mode analysis.

Source: http://arxiv.org/abs/hep-th/0308029v1

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Sep 18, 2013
09/13

by
Sang-Jin Sin; Ismail Zahed

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We note that the energy loss in ${\cal N}=4$ SYM measures directly the spatial string tension $\sigma_S=\pi\sqrt{\lambda}T^2/2$ which is at the origin of the area law for large spatial Wilson loops. We show that the latter reflects on the nonperturbative nature of Ampere's law in ${\cal N}=4$ SYM both in vacuum and at finite temperature.

Source: http://arxiv.org/abs/hep-ph/0606049v2

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Sep 21, 2013
09/13

by
Sang-Jin Sin; Ismail Zahed

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We study the non-linear propagation of radiation in {\cal N=4} SYM at zero and finite temperature using the refined radius/scale duality in AdS/CFT. We argue that a pulse radiation by a quark at the boundary should be described holographically by a "point like object" passing through the center of the AdS bulk. We find that at finite temperature, the radiation stalls at a distance of $1/\pi T$ with a natural geometric and holographic interpretation. Indeed, the stalling is the...

Source: http://arxiv.org/abs/hep-th/0407215v3

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Sep 23, 2013
09/13

by
Sang-Jin Sin; Yang Zhou

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We propose a Dirac-Born-Infeld (DBI) D5 vertex brane plus N_c fundamental strings configuration to describe a baryon probe in strongly coupled gauge theory with gluon condensation at finite temperature via AdS/CFT correspondence. We investigate properties of this configuration in a dilaton deformed AdS_5\times S^5 background, in which IIB string theroy is dual to super Yang-Mills thery in a state with a constant self-dual gauge field (F_{mn}=F^*_{mn}) background. We find that for most values of...

Source: http://arxiv.org/abs/0904.4249v2

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Sep 19, 2013
09/13

by
Taichi Itoh; Sang-Jin Sin

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After reviewing D-branes as conjugacy classes and various charge quantizations (modulo $k$) in WZW model, we develop the classification and systematic construction of all possible untwisted D-branes in Lie groups of A-D-E series. D-branes are classified according to their positions in the maximal torus. The moduli space of D-branes is naturally identified with a unit cell in the weight space which is exponentiated to be the maximal torus. However, for the D-brane classification, one may...

Source: http://arxiv.org/abs/hep-th/0206238v3

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Jul 19, 2013
07/13

by
Kwanghyun Jo; Sang-Jin Sin

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We calculate the thermal spectral function of SYM plasma with finite density using holographic technique. We take the RN-AdS black hole as the dual gravity theory. In the presence of charge, vector modes of gravitational and electromagnetic perturbation are coupled with each other. By introducing master variables for these modes, we solve the coupled system and calculate spectral function. We also calculated photoemission rate of SYM plasma from spectral function for light like momentum, AC...

Source: http://arxiv.org/abs/1005.0200v2

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Sep 21, 2013
09/13

by
Sunggeun Lee; Sang-Jin Sin

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Using the AdS/CFT correspondence we study UV behavior of Wilson loops in various noncommutative gauge theories. We get an area law in most cases and try to identify its origin. In D3 case, we may identify the the origin as the D1 dominance over the D3: as we go to the boundary of the AdS space, the effect of the flux of the D3 charge is highly suppressed, while the flux due to the D1 charge is enhenced. So near the boundary the theory is more like a theory on D1 brane than that on D3 brane....

Source: http://arxiv.org/abs/hep-th/0104232v5

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Sep 18, 2013
09/13

by
Takaaki Ishii; Sang-Jin Sin

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We consider a holographic superconductor with homogeneous impurities added. We start with the holographic Abelian-Higgs model for s-wave superconductivity, and turn on a coupling between the gauge field and a new massive gauge field that is introduced for impurities, whose effect is examined in the probe limit. We find that the condensation of the massive gauge field is induced in the superconducting phase. When the coupling is sufficiently large, the mass gap in the optical conductivity...

Source: http://arxiv.org/abs/1211.1798v2

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Sep 23, 2013
09/13

by
Julian Lee; Sang-Jin Sin

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We generalize the M-theoretic duality of Schmaltz and Sundrum to the product group SU(N) x SU(N') case. We show that the type IIA brane configurations for dual gauge theories are in fact two special limits of the same M-theory 5-brane, just as in the case of the simple SU(N) group.

Source: http://arxiv.org/abs/hep-th/9806170v2

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Sep 17, 2013
09/13

by
Taichi Itoh; Sang-Jin Sin

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We study the classification of D-branes in all compact Lie groups including non-simply-laced ones. We also discuss the global structure of the quantum moduli space of the D-branes. D-branes are classified according to their positions in the maximal torus. We describe rank 2 cases, namely $B_2$, $C_2$, $G_2$, explicitly and construct all the D-branes in $B_r$, $C_r$, $F_4$ by the method of iterative deletion in the Dynkin diagram. The discussion of moduli space involves global issues that can be...

Source: http://arxiv.org/abs/hep-th/0207077v4

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Sep 18, 2013
09/13

by
Chanyong Park; Sang-Jin Sin

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We study the cosmology of the Brans-Dicke theory with perfect fluid type matter. In our previous work, we found exact solutions for any Brans-Dicke parameter $\omega$ and for general parameter $\gamma$ of equation of state. In this paper we further study the cosmology of these solutions by analyzing them according to their asymptotic behaviors. The cosmology is classified into 19 phases according to the values of $\gamma$ and $\omega$. The effect of the cosmological constant to the Brans-Dicke...

Source: http://arxiv.org/abs/gr-qc/9901059v2

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Sep 18, 2013
09/13

by
Sang-Jin Sin; Yang Zhou

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We study the relations between two different approaches to the holographic Renormalization Group (RG) flow at the dual gravity level: One is the radial evolution of the classical equation of motion and the other is the flow equation given by the holographic Wilsonian RG coming from the cut off independence. Apparently, the two flows look different. We give general proofs that the two flows are actually equivalent. The role of the momentum continuity (MC) is essential. We show that MC together...

Source: http://arxiv.org/abs/1102.4477v2

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Sep 22, 2013
09/13

by
Chanyong Park; Sang-Jin Sin

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We show that the D-instanton in the $AdS_5 \times S^5$ background is a wormhole connecting the background $AdS_5 \times S^5$ to the flat space $\bf R^{10}$ located at the position of the D-instanton. By a $SL(2,{\bf R})$ rotation of type IIB theory, we can make the {\it global} geometry flat in string frame. We also find that, due to the tight relation between the dilaton and the axion, there is no $SL(2,{\bf R})$ element that takes strong string coupling to weak one without making the axion...

Source: http://arxiv.org/abs/hep-th/9807156v2

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Sep 18, 2013
09/13

by
Yunseok Seo; Sang-Jin Sin

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We study nuclear symmetry energy of dense matter using holographic QCD. We calculate it in a various holographic QCD models and show that the scaling index of the symmetry energy in dense medium is almost invariant under the smooth deformation of the metric as well as the embedding shape of the probe brane. We find that the scaling index depends only on the dimensionality of the branes and space-time. Therefore the scaling index of the symmetry energy characterizes the universality classes of...

Source: http://arxiv.org/abs/1201.0459v1

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Sep 22, 2013
09/13

by
Chanyong Park; Sang-Jin Sin

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We study the effect of the solitonic degrees of freedom in string cosmology following the line of Rama. The gas of solitonic p-brane is treated as a perfect fluid in a Brans-Dicke type theory. In this paper, we find exact cosmological solutions for any Brans-Dicke parameter $\omega$ and for general parameter $\gamma$ of equation of state and classify the cosmology of the solutions on a parameter space of $\gamma$ and $\omega$.

Source: http://arxiv.org/abs/hep-th/9707003v2

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Sep 20, 2013
09/13

by
Shin Nakamura; Sang-Jin Sin

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We consider a gravity dual description of time dependent, strongly interacting large-Nc N=4 SYM. We regard the gauge theory system as a fluid with shear viscosity. Our fluid is expanding in one direction following the Bjorken's picture that is relevant to RHIC experiments. We obtain the dual geometry at the late time that is consistent with dissipative hydrodynamics. We show that the integration constants that cannot be determined by hydrodynamics are given by looking at the horizon of the dual...

Source: http://arxiv.org/abs/hep-th/0607123v2

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Sep 20, 2013
09/13

by
Yunseok Seo; Sang-Jin Sin

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We study the baryon vertex (BV) in the presence of medium using DBI action and the force balance condition between BV and the probe branes. We note that a stable BV configuration exists only in some of the confining backgrounds. For the system of finite density, the issue is whether there is a canonical definition for the baryon mass in the medium. In this work, we define it as the energy of the deformed BV satisfying the force balance condition (FBC) with the probe brane. With FBC, lengths of...

Source: http://arxiv.org/abs/0802.0568v3

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Sep 18, 2013
09/13

by
Chanyong Park; Sang-Jin Sin

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We consider moving-brane-solutions in AdS type back ground. In the first Randall-Sundrum configuration, there are two branes at fixed points of the orbifold symmetry. We point out that if one brane is fixed and the other brane is moving, the configuration is still a solution provided the moving brane has a specific velocity determined by its tension and bulk cosmological constant. In the absence of the $\bf Z_2$ symmetry, we can construct multi-brane configurations by patching AdS-Schwarzshild...

Source: http://arxiv.org/abs/hep-th/0005013v2

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Sep 22, 2013
09/13

by
Matthias Klein; Sang-Jin Sin

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We study the duality of $\cN=1$ gauge theories in the presence of a massless adjoint field and massive quarks by calculating the superpotential using the Dighkgraaf-Vafa matrix model and by comparing with the previous result coming from Kutasov duality. The Kutasov duality method gives a result in which one instanton term is absent. The matrix model method confirms it and also show that the absence of the one instanton term is related to the masslessness of the adjoint field.

Source: http://arxiv.org/abs/hep-th/0310078v2

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Sep 23, 2013
09/13

by
Sunggeun Lee; Sang-Jin Sin

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We study the condensation of localized tachyon in non-supersymmetric orbifold ${\C^2/\Z_n}$. We first show that the G-parities of chiral primaries are preserved under the condensation of localized tachyon(CLT) given by the chiral primaries. Using this, we finalize the proof of the conjecture that the lowest-tachyon-mass-squared increases under CLT at the level of type II string with full consideration of GSO projection. We also show the equivalence between the $G$-parity given by $G=[jk_1/n]+...

Source: http://arxiv.org/abs/hep-th/0312175v3

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Sep 24, 2013
09/13

by
Sunggeun Lee; Sang-Jin Sin

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Recently Dabholkar and Vafa proposed that closed string tachyon potential for non-supersymmetric orbifold $\C/\Z_3$ in terms of the solution of a $tt^*$ equation. We extend this result to $\C^2/\Z_n$ for $n=3,4,5$. Interestingly, the tachyon potentials for $n=3$ and 4 are still given in terms of the solutions of Painleve III type equation that appeared in the study of $\C^1/\Z_3$ with different boundary conditions. For $\C^2/\Z_5$ case, governing equations are of generalized Toda type. The...

Source: http://arxiv.org/abs/hep-th/0412247v2

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Sep 21, 2013
09/13

by
Kwanghyun Jo; Youngman Kim; Sang-Jin Sin

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We revisit holographic mesons in the D4/D6 model to study holographic light vector mesons and the properties of heavy quarkonium in confining and deconfining phases. To treat the light mesons and heavy quarkonium on the same footing, we use the same compactification scale MKK in both systems. We observe that like scalar and pseudo-scalar mesons the vector meson mass is linearly proportional to the square root of the quark mass, when the quark mass is large. With a MKK fixed by light meson...

Source: http://arxiv.org/abs/1104.2098v1

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Sep 22, 2013
09/13

by
Changhyun Ahn; Soonkeon Nam; Sang-Jin Sin

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We describe orientifold operation defining O3 plane in the conifold background by deriving it from that of O4 plane in the Type IIA brane construction by T-duality. We find that both $O3^+$ and $O3^-$ are at the tip of the cone so that there is no net untwisted RR charge. RG analysis shows that we need two `fractional' branes for the conformal invariance in orientifolded conifold. We argue that the gravity solution is the same as Klebanov and Tsyetlin since SUGRA cannot distinguish the...

Source: http://arxiv.org/abs/hep-th/0106093v5

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Sep 23, 2013
09/13

by
Youngman Kim; Yumi Ko; Sang-Jin Sin

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We study the density driven symmetry breaking in holographic superconductors by considering the positive mass squared case. We show that even for the positive $m^2$, a scalar condensation still forms, provided the chemical potential is high enough. As $m^2$ increases, the phase space folds due to the non-linearity of the equations of motion, and two nearby points in the phase space can represent symmetry breaking and preserving configurations respectively. The phase space defined by the set of...

Source: http://arxiv.org/abs/0904.4567v2

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Sep 23, 2013
09/13

by
Yoshinori Matsuo; Sang-Jin Sin; Yang Zhou

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We consider quark-gluon plasma with chemical potential and study renormalization group flows of transport coefficients in the framework of gauge/gravity duality. We first study them using the flow equations and compare the results with hydrodynamic results by calculating the Green functions on the arbitrary slice. Two results match exactly. Transport coefficients at arbitrary scale is ontained by calculating hydrodynamics Green functions. When either momentum or charge vanishes, transport...

Source: http://arxiv.org/abs/1109.2698v1

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Sep 19, 2013
09/13

by
Chanyong Park; Sang-Jin Sin; Sunggeun Lee

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We study the effect of the Dp-brane gas in string cosmology. When one kind of Dp-brane gas dominates, we find that the cosmology is equivalent to that of the Brans-Dicke theory with the perfect fluid type matter. We obtain $\gamma$, the equation of state parameter, in terms of p and the space-time dimension.

Source: http://arxiv.org/abs/hep-th/9911117v1

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Sep 22, 2013
09/13

by
Soonkeon Nam; Kyungho Oh; Sang-Jin Sin

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We consider brane configurations in M-theory describing N=1 supersymmetric gauge theories and using the parametric representation of the brane configurations, we calculate the superpotentials for various cases including multiple gauge groups or fermions. For SU(n) N=1 SQCD with $N_f$ fermion case ($N_f < N_c)$, we find that the superpotential from M-theory and the gauge theory agree precisely. This gives a direct evidence of the validity of Witten's M-theory method for calculating the super...

Source: http://arxiv.org/abs/hep-th/9707247v2

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Sep 23, 2013
09/13

by
Sunggeun Lee; Chanyong Park; Sang-Jin Sin

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We study the cosmology of the Brans-Dicke(BD) theory coupled to perfect fluid type matter. In our previous works, the case where matter is coming from the Ramond-Ramond sector of the string theory was studied. Here, we study the case where matter is coming from the NS-NS sector. Exact solutions are found and the cosmology is classified according to the values of $\gamma$, the parameter of the equation of state and $\omega$, Brans-Dicke parameter. We find taht, in string frame, there are...

Source: http://arxiv.org/abs/gr-qc/9909011v1

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Sep 20, 2013
09/13

by
Yunseok Seo; Sang-Jin Sin; Yang Zhou

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We consider the self-energy of strongly interacting fermions in the medium using gauge/gravity duality of $D4/D8$ system. We study the mass generation of the thermal and/or dense medium and the collective excitation called plasmino, by considering the spectral function of fermion and its dispersion relation. Our results are very different from those of the hard thermal loop method: for zero density, there is no thermal mass or plasmino in any phase. Plasmino in deconfined phase is not allowed...

Source: http://arxiv.org/abs/1205.3377v3

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Sep 23, 2013
09/13

by
Shi Pu; Sang-Jin Sin; Yang Zhou

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We build a holographic description of non-relativistic system for superconductivity in strongly interacting condensed matter via gauge/gravity duality. We focus on the phase transition and give an example to show that a simple gravitational theory can provide a non-relativistic holographical dual description of a superconductor. There is also a critical temperature like the relativistic case, below which a charged condensation field appears by a second order phase transition and the (DC)...

Source: http://arxiv.org/abs/0903.4185v3

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Sep 22, 2013
09/13

by
Xian-Hui Ge; Sang-Jin Sin

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We derive a new acoustic black hole metric from the Abelian Higgs model. In the non-relativistic limit, while the Abelian Higgs model becomes the Ginzburg-Landau model, the metric reduces to an ordinary Unruh type. We investigate the possibility of using (type I and II) superconductors as the acoustic black holes. We propose to realize experimental acoustic black holes by using spiral vortices solutions from the Navier-stokes equation in the non-relativistic classical fluids.

Source: http://arxiv.org/abs/1001.0371v3

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Sep 23, 2013
09/13

by
E. Shuryak; Sang-Jin Sin; Ismail Zahed

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In the context of the AdS/CFT correspondence we discuss the gravity dual of a heavy-ion-like collision in a variant of ${\cal N}=4$ SYM. We provide a gravity dual picture of the entire process using a model where the scattering process creates initially a holographic shower in bulk AdS. The subsequent gravitational fall leads to a moving black hole that is gravity dual to the expanding and cooling heavy-ion fireball. The front of the fireball cools at the rate of $1/\tau$, while the core cools...

Source: http://arxiv.org/abs/hep-th/0511199v3

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Sep 23, 2013
09/13

by
Xian-Hui Ge; Sang-Jin Sin

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We compute the dimensionality dependence of $\eta/s$ for charged black branes with Gauss-Bonnet correction. We find that both causality and stability constrain the value of Gauss-Bonnet coupling constant to be bounded by 1/4 in the infinite dimensionality limit. We further show that higher dimensionality stabilize the gravitational perturbation. The stabilization of the perturbation in higher dimensional space-time is a straightforward consequence of the Gauss-Bonnet coupling constant bound.

Source: http://arxiv.org/abs/0903.2527v3

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Sep 19, 2013
09/13

by
Mannque Rho; Sang-Jin Sin; Ismail Zahed

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Dense QCD at zero temperature with a large number of colors is a crystal. We show that in the holographic dual description, the crystal is made out of pairs of dyons with $e=g=\pm 1$ charges in a salt-like arrangement. We argue that with increasing density the dyon masses and topological charges equalize, turning the salt-like configuration to a bcc of half-instantons. The latter is dual to a cubic crystal of half-skyrmions. We estimate the transition from an fcc crystal of instantons to a bcc...

Source: http://arxiv.org/abs/0910.3774v2

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Sep 21, 2013
09/13

by
Yoshinori Matsuo; Sang-Jin Sin; Yang Zhou

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We consider the hydrodynamics of strongly interacting quark gluon plasma in finite temperature and density using the holographic duality of charged black hole in anti DeSitter space. We calculate the transport coefficients at arbitrary energy scale by considering the holographic screen at finite radial position. We first calculate the flow of sound velocity in this method and check the consistence with previous result. Then we calculate diffusion constant of charge and find that Einstein...

Source: http://arxiv.org/abs/1204.6627v1

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Sep 21, 2013
09/13

by
Mannque Rho; Sang-Jin Sin; Ismail Zahed

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Using the AdS/CFT correspondence and the eikonal approximation, we evaluate the elastic parton-parton scattering amplitude at large $N$ and strong coupling $g^2N$ in N=4 SYM. We obtain a scattering amplitude with a Regge behavior that unitarizes at large $\sqrt{s}$.

Source: http://arxiv.org/abs/hep-th/9907126v2

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Sep 22, 2013
09/13

by
Seung-geun Lee; Sang-Jin Sin

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We study the effect of the solitonic degree of freedom in string cosmology following the line of Rama. The gas of solitonic p-brane is treated as a perfect fluid in a Brans-Dicke type theory. In this paper, we find analytic solutions for a few solvable cases of equation of states with general Brans-Dicke parameter $\omega$ and study the cosmology of the solutions. In some cases the solutions are free from initial singularity.

Source: http://arxiv.org/abs/hep-th/9707001v1

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Jun 30, 2018
06/18

by
I. Y. Park; Shigenori Seki; Sang-Jin Sin

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In a scattering process, the final state is determined by an initial state and an S-matrix. We focus on two-particle scattering processes and consider the entanglement between these particles. For two types initial states; i.e., an unentangled state and an entangled one, we calculate perturbatively the change of entanglement entropy from the initial state to the final one. Then we show a few examples in a field theory and in quantum mechanics.

Topic: High Energy Physics - Theory

Source: http://arxiv.org/abs/1412.7894